Furnace



C. J. HUBER FURNACE Filed Dec. 16, 1925 Patented Apr. 17, 1928.

UNITED STATES PATENT OFFICE.

CHARLES J. HUBER, 0F BALTIMORE, MARYLAND.

FURNACE.

Application filed December 16, 1925. Serial No. 75,675.

An important obstacle to the use of coal burning furnaces in the generation of power, particularly in the vicinity of large cities. is the smoke nuisance resulting from the discharge from the stack of large quantities of unconsumed carbon, also the less noticeable but probably not less important discharge of carbon monoxide which also represents unconsumed carbon. These incidents affect the general public and the excessive discharge of smoke is in most localities'prohibited by law. Another incident to incomplete combustion is the resulting low percentage of efliciency or loss of heat units due to the discharge through the stack of this unconsumed fuel.

In many instances the smoke nuisance is partially overcome by the admission to the furnace of an excess of air which dilutes the materials discharged from the stack and makes the smoke less apparent and also consumes or partially consumes the excess carbon. However, the. admission of an excess of air to the furnace results in a tremendous loss of economy in the form of heat units consumed in heating the excess air as it passes through the furnace and over the heating surfaces of the boiler.

The present invention relates to a furnace structure and furnace practice whereby the maximum of economy is achieved, the carbon and carbon monoxide being completely con sumed to carbon dioxide, so that the smoke is entirely eliminated.

By the structure and furnace practice herein described, the applicant has succeeded in generating practically one hundred per cent of the heat units determined by analysis to be present in the fuel, a result not previously attained by any furnace practice or furnace structure.

In the accompanying drawing I have illustrated a furnace structure embodying the features of my invention in the preferred form.

In the drawing the figure is a vertical central section extending from the front to the rear of a furnace of the preferred commercial type as now manufactured and sold.

Referring to the drawings by numerals. the apparatus as shown comprises a furnace structure 1 having a front wall 2, arch 3, downwardly and rearwardly inclined grate 4, comprising rocking sections 26 for supporting and moving the fuel downward and to the rear as it is burned, drop bar 6 at the rear, feed opening 7, coking shelf 8, and refractory heat storing and radiating members 10 and .11 above and below the coking shelf, air inlet 12 above the coking shelf and air inlets 14 and 15, 15 forward of and beneath the coking shelf. There is also a coke pusher 19 of any suitable type by which the cokcd fuel is dislodged from the shelf 8 and dropped into the combustion space. There is also a coke ushing opening 20 above the Coke pusher tiirough which a bar may be inserted to move the coke from the coking shelf. The member 10 forms the top wall of the feed opening.

The arch 3 is supported by channels 16 which are placed with their flanges horizon tal and approaching each other, forming a transverse air passage 17 in the front wall. The air draft takes up the heat of the arch and serves to cool and preserve the iron work of the furnace frame structure, and the waste heat from the arch serves to heat the air and supply a draft of hot air at the desired point.

The feed opening 7 leading from the hopper 18 supplies fuel to the coking shelf 8, where it is heated to a high temperature by the radiation from the fire, and, further, by heat radiation and conductlon from the heat storing and radiating members 10 and 11 above and below the coking shelf, which members when the furnace is in operation, attain and retain a very high temperature.

Air is also admitted beneath and in front of the coking shelf in any preferred manner as by way of the fire-door 14 which is provided at the front beneath the hopper to give access to the fire for any and all purposes during the operation of the furnace, as hand stoking. removing clinkers or the like under extraordinary conditions, or it may be admitted by way of the ash-pit door 15, passing upward through openings 15', 15" at the front of the grate, which openingsare so far forward as not to be clogged by the fuel dropping from the coking shelf.

When the furnace is in operation, air admitted from beneath and forward of the coking shelf as described, passes upward as indicated by the arrows over the fresh fuel on the grate and mingles with the gases given off by the fuel here and on the coking shelf. the amount of air admitted being reduced to the minimum to prevent loss of heat by heating excess air in the furnace. Air admitted by way of the fire door 14 is passed throu h openings 24 therein closed and regulate; by a shutter 25 and a similar Shutter 9 maybe provided in the ash pit In the preferred form of furnace the downward and rearward incline of the grate is determined to give exactly the right pitch, and fuel feed, and the motion of the fuel to the rear as it is consumed, is further assisted by the manually or power-driven stoking grate 4 composed of a series of rocking grate sections 26, each of which is pivoted at the rear on projecting journal members 27 at each side, the rear surface being preferably rounded at 28, and the forward swinging surface 29 being closed and in the form of an arcuate shield concentric with the journal, the shield 29 of each section being normally in contact or almost in contact with the rear surface 28 of the next grate section on the front. The grate sections are provided with slots or openings to admit air to the fire and to cool the grate, the openings being between the shield 29 and the journal 27, and each section has a downwardly and rearwardly inclined arm 30, the arms being pivotall connected to longitudinal actuating mem ers 31 of which there are two for each unit of the furnace or set of grate sections. The sections are in this way-connected together in series of alternate grate sections, as shown. The parallel members 31 are separately actuated by means of connecting rods 32, 33 either by hand or by mechanical means. The drop bar 6, which is pivoted at 34 is controlled by a suitable 'drop bar control rod 35.

In the operation of the. furnace structure described in accordance with the preferred practice, the fuel is first fed to the coking shelf 8 where it is subjected to a high temperature due to direct radiation from the re and to radiation and conduction from the heating and radiating members 10 and 11 which are of resistive materials continuously heated by direct radiation from the fire. The material is fed or dumped from the coking shelf after it is suitably coked in any suitable manner, and piles up on the grate as shown, an air is admitted both beneath and forward of the coking shelf and above the coking shelf beneath the heating member 10, so that the air is passed over the unburned coked fuel at the front of the furnace and over the green fuel being coked on the shelf, the draft from the bottom thus passed upwardly in contact with the hot fuel being further mixed with a draft of air or hot air from the air opening 12 at the top, which is passed over the entire surface of the fuel being coked, the two drafts being mingled and passed to the rear through the hottest part of the furnace, where the mixed air and gases and carbon are in turn mingled with the products of combustion at an exthe agitation being just sufficient to maintain a regular flow of the burning mass and drop the ash and break the clinkers. The burned material accumulates at the rear on the drop bar, and is dropped from time to time by the operator as seems necessary. The unburned solid thus released is incombustible mineral, the carbon and other combustible constituents of the fuel being completely burned.

I have thus described specifically and in detail a single embodiment of my furnace and method of burning fuel in order that the nature, operation and manner of practicing the same may be clearl understood; however, the specific terms herein are used in a descriptive rather than in a limiting sense, the scope of the invention being defined in the claims. 7

What I claim and desire to secure by Let ters Patent is:

1. In a furnace having a feed 0 ening, a grate, a coking shelf extending ackward into the furnace at the lower side of the feed opening, above the grate and above the normal position of the fuel on the grate, a top wall exposed to radiation from the fire and extending backward above the shelf, the coking shelf and to wall being of heavy resistive material an serving as heat reservoirs to store heat and transmit it to the fuel, the furnace structure comprising a free and unobstructed passage for admitting outside air beneath and forward of the shelf, and a passage admitting air to the feed opening at the top surface of the fuel on the shelf.

2. In a furnace having a feed opening, a grate, a coking shelf extending backward into the furnace at the lower side of the feed opening above the grate, and above the normal position of the fuel on the grate, the feed opening having a top wall exposed to radiation from the fire and extending backward above the shelf, the coking shelf and top wall being of heavy resistive material and serving as heat reservoirs to store heat and transmit it to the fuel, the furnace structure having a free and unobstructed passage beneath and forward of the shelf for admitting air and a passage admitting air to the feed opening at the top surface of the fuel on the shelf, a downwardly and rearwardly inclined grate with means for supporting and releasing the burned ash at the rear, the grate being formed of rocking sections and provided with actuating means for the same for gradually moving the burning mass of fuel downwardly and to the rear voirs to store heat and transmit it to the as combustion thereof progresses. fuel, the furnace structure comprising a 3. In a furnace having a feed opening, a free and unobstructed air passage beneath ll te, an arch, a coking shelf extending and forward of the shelf, and a passage ad- 5 sdkward into the furnace at the lower side mittmg air to the feed opening at the top of the feed opening above the grate and surface of the fuel on the shelf, means for above the normal position of the fuel on the heating the air admitted to the feed opening grate, a top wall which forms part of the comprising an air passage in the arch lead- 2 wall and is ex osed to radiation from the ing to said air opening.

fire and exten s backward above the shelf, Signed by me at Baltimore, Maryland,

the coking shelf and topgvall being of heavy this 12th day of December, 1925. resistive material and serving as heat reser- CHARLES J. HUBER.

CERTIFICATE OF CORRECTION.

atent No. l,6v66,4l8. Granted April 17, 1928. to

CHARLES J. HUBER.

It is hereby certified that error appears in the printed above numbered patent requiring correction as follows: 3, for the word "wall" read "arch" be read with this correction therei of the case in the Patent Office.

Signed and sealed this 15th day of May, A. D. 1928.

specification of the Page 3, line 9, claim and that the said Letters Patent should n that the same may conform loathe record i i M. J. Moore 8 i eal) Acting Commissioner of Patents.

ing mass of fuel downwardly and to the rear voirs to store heat and transmit it to the as combustion thereof progresses. fuel, the furnace structure comprising a 3. In a furnace having a feed opening, a free and unobstructed air passage beneath ll te, an arch, a coking shelf extending and forward of the shelf, and a passage ad- 5 sdkward into the furnace at the lower side mittmg air to the feed opening at the top of the feed opening above the grate and surface of the fuel on the shelf, means for above the normal position of the fuel on the heating the air admitted to the feed opening grate, a top wall which forms part of the comprising an air passage in the arch lead- 2 wall and is ex osed to radiation from the ing to said air opening.

fire and exten s backward above the shelf, Signed by me at Baltimore, Maryland,

the coking shelf and topgvall being of heavy this 12th day of December, 1925. resistive material and serving as heat reser- CHARLES J. HUBER.

CERTIFICATE OF CORRECTION.

atent No. l,6v66,4l8. Granted April 17, 1928. to

CHARLES J. HUBER.

It is hereby certified that error appears in the printed above numbered patent requiring correction as follows: 3, for the word "wall" read "arch" be read with this correction therei of the case in the Patent Office.

Signed and sealed this 15th day of May, A. D. 1928.

specification of the Page 3, line 9, claim and that the said Letters Patent should n that the same may conform loathe record i i M. J. Moore 8 i eal) Acting Commissioner of Patents. 

